implement send back file effect, add errors to fix potential crashes

Author: Pikachu920

src/main/java/com/pikachu/webaddon/skript/effects/EffSendBack.java

@@ -44,4 +44,5 @@ protected void execute(Event e) {
 	public String toString(Event e, boolean debug) {
 		return "send back " + response.toString(e, debug);
 	}
+
 }

src/main/java/com/pikachu/webaddon/skript/effects/EffSendBackFile.java

@@ -0,0 +1,59 @@
+package com.pikachu.webaddon.skript.effects;
+
+import ch.njol.skript.ScriptLoader;
+import ch.njol.skript.Skript;
+import ch.njol.skript.lang.Effect;
+import ch.njol.skript.lang.Expression;
+import ch.njol.skript.lang.SkriptParser;
+import ch.njol.skript.registrations.EventValues;
+import ch.njol.util.Kleenean;
+import org.bukkit.event.Event;
+import spark.Response;
+
+import javax.servlet.http.HttpServletResponse;
+import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Paths;
+import java.util.Arrays;
+
+public class EffSendBackFile extends Effect {
+
+	static {
+		Skript.registerEffect(EffSendBackFile.class, "send back file %string%");
+	}
+
+	private Expression<String> file;
+
+	@Override
+	public boolean init(Expression<?>[] exprs, int i, Kleenean kleenean, SkriptParser.ParseResult parseResult) {
+		if (ScriptLoader.getCurrentEvents() != null && Arrays.stream(ScriptLoader.getCurrentEvents())
+				.anyMatch(event -> EventValues.getEventValueGetter(event, Response.class, 0) != null)) {
+			file = (Expression<String>) exprs[0];
+			return true;
+		}
+		Skript.error("You may only use 'send back' in events with a response");
+		return false;
+	}
+
+	@Override
+	protected void execute(Event e) {
+		Response response = EventValues.getEventValue(e, Response.class, 0);
+		String file = this.file.getSingle(e);
+		if (response != null && file != null) {
+			try {
+				byte[] fileData = Files.readAllBytes(Paths.get(file));
+				HttpServletResponse raw = response.raw();
+				raw.getOutputStream().write(fileData);
+				raw.getOutputStream().flush();
+				raw.getOutputStream().close();
+			} catch (IOException ignored) {
+			}
+		}
+	}
+
+	@Override
+	public String toString(Event e, boolean debug) {
+		return "send back file" + file.toString(e, debug);
+	}
+
+}

src/main/java/com/pikachu/webaddon/skript/scopes/http/ScopeHTTPServer.java

@@ -23,12 +23,15 @@
 import spark.Service;
 
 import java.util.ArrayList;
+import java.util.HashSet;
 import java.util.List;
+import java.util.Set;
 import java.util.UUID;
 
 public class ScopeHTTPServer extends EventScope {
 
 	private static boolean parsing;
+	private static Set<Integer> usedPorts = new HashSet<>();
 
     static {
         Skript.registerEvent("web server", ScopeHTTPServer.class, StubBukkitEvent.class,
@@ -56,44 +59,47 @@ public Response get(HTTPRequestEvent arg) {
 
     @Override
     public boolean init(Literal<?>[] args, int matchedPattern, SkriptParser.ParseResult parseResult) {
-		parsing = true;
         SectionNode sectionNode = (SectionNode) SkriptLogger.getNode();
         stringRep = sectionNode.getKey();
         String stringPort = parseResult.regexes.get(0).group();
         if (stringPort.matches("\\d{1,5}")) {
             port = Integer.parseInt(stringPort);
+			if (usedPorts.contains(port)) {
+				Skript.error("There is already a web server running on port " + port);
+				return false;
+			}
         } else {
             Skript.error("'" + stringPort + "' is not a valid port");
-			parsing = false;
             return false;
         }
         if (stringRep.startsWith("on")) {
             Skript.error("You may not use 'on' with a web server!");
-			parsing = false;
             return false;
         }
 
         for (Node node : sectionNode) {
             Util.setKey(node, ScriptLoader.replaceOptions(node.getKey()));
             if (!(node instanceof SectionNode)) {
                 Skript.error("A web server may only contain request scopes");
-				parsing = false;
                 return false;
             }
             if (RequestScope.getPatterns().stream().noneMatch(p -> node.getKey().matches(p))) {
                 Skript.error("'" + node.getKey() + "' is not a request scope (e.g. 'get /index:')");
-				parsing = false;
                 return false;
             }
             rawNodes.add((SectionNode) node);
         }
+		if (rawNodes.isEmpty()) {
+			Skript.error("A web server without any routes is useless");
+			return false;
+		}
         Util.clearSectionNode(sectionNode);
-		parsing = false;
         return true;
     }
 
     @Override
     public void load() {
+		usedPorts.add(port);
         server = Service.ignite().port(port);
         for (SectionNode node : rawNodes) {
             RequestScope scope = (RequestScope) Condition.parse(node.getKey(), "Can't understand this scope: '" + node.getKey() + "'");
@@ -112,6 +118,7 @@ public void unregister(Trigger t) {
 		// workaround for spark npe
 		server.options("workaroundForSparkNpe" + UUID.randomUUID().toString(), (req, resp) -> "you shouldn't be seeing this");
         server.stop();
+		usedPorts.remove(port);
     }
 
     @Override

src/main/java/com/pikachu/webaddon/skript/scopes/http/requests/SimpleRequestScope.java

@@ -17,9 +17,6 @@ public static void register(Class<? extends SimpleRequestScope> clazz, String ty
 
 	@Override
 	public final boolean init(Expression<?>[] exprs, int matchedPattern, Kleenean isDelayed, SkriptParser.ParseResult parseResult) {
-		if (!hasSection()) {
-			return false;
-		}
 		if (parseResult.regexes.size() != 1) {
 			throw new UnsupportedOperationException("A " + getClass().getSimpleName() + " must have only one regex!");
 		}

src/main/java/com/pikachu/webaddon/util/scope/EffectSection.java

@@ -37,6 +37,7 @@ public abstract class EffectSection extends Condition {
     private TriggerSection trigger = null;
     private boolean hasIfOrElseIf = false;
     private boolean executeNext = true;
+	private boolean hasSection;
     private String asInScript;
 
     public EffectSection() {
@@ -45,6 +46,7 @@ public EffectSection() {
         Node n = SkriptLogger.getNode(); //Skript sets the node before parsing this 'effect'
         if (n == null || !(n instanceof SectionNode)) //Check in case it wasn't loaded as inline condition
             return;
+		hasSection = true;
         asInScript = n.getKey();
         //True if it was used as condition
         hasIfOrElseIf = StringUtils.startsWithIgnoreCase(n.getKey(), "if ") || StringUtils.startsWithIgnoreCase(n.getKey(), "else if ");
@@ -176,7 +178,7 @@ public void loadSection(String name, boolean setNext, Class<? extends Event>...
      * @return True if it has
      */
     public boolean hasSection() {
-        return section != null || trigger != null;
+		return hasSection;
     }
 
     /**